


High Seas Halloween

by Fauxpines



Category: Gravity Falls
Genre: Drinking, Drug Use, F/M, Halloween, Halloween Costumes, Incest, Sailing, Sibling Incest, Twincest, Underage Drinking
Language: English
Status: Completed
Published: 2020-10-31
Updated: 2020-10-31
Packaged: 2021-03-09 05:54:48
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,150
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27299806
Author URL: https://archiveofourown.org/users/Fauxpines/pseuds/Fauxpines
Summary: When Pacifica and the gang are invited onto Marius' yacht for some fun in international waters, she finds that being outside the law means something different to some people.
Relationships: Dipper Pines/Mabel Pines, Pacifica Northwest/Dipper Pines
Comments: 3
Kudos: 30





	High Seas Halloween

**Author's Note:**

> Idea for this fic was inspired by this pic and the mind of BizarreJoe
> 
> https://twitter.com/PinchiVersus/status/1318344292394541059?s=19

Halloween on a yacht in international waters sounded like a peculiar idea. But when Marius and Grenda invited Pacifca and all their friends to a party, they were all overjoyed to have such an experience. The staff would be minimal and paid extra to be discreet along with the captain, ensuring the teens attending could have fun without worry. Pacifica was used to these parties as she was invited to them much like Marius was invited to many of her family hosted events. With Grenda being his girlfriend, and Pacifca now having dated Dipper for a year, everyone coming was expected. 

The gang of teens that joined all were dressed up and ready to set sail. Marius and Grenda dressed as barbarian warriors with appropriate loin cloth attire and fake weapons to tie the look together. Candy dressed as a peculiar cartoon character that looked like an elongated rainbow unicorn. Wendy went as a supernatural slasher from a classic horror film with a bladed gloved hand to give her friends a fright. Pacifica thought all their costumes were cute and well made. However, she believed hers and Dipper's costume were the better ones. 

Pacifica and Dipper also went the way of the couple's costume. Dipper set the theme with a comfortable red robe, slippers, pipe, and a sailor's hat, embodying the look of one of the fathers of pinup modeling. Pacifica completed the look wearing a purple, strapless, corset that fit her form, a pair of stockings and high heels, a white puffball for a cottontail, and a bunny eared headband. Dipper was surprised at Pacifica's acceptance of the idea to do such a suggestive costume and be his little bunny. But what got them more was Mabel's inclusion, making it a group costume. 

Pacifica had to admit though it was hard to argue why Mabel couldn't also be a bunny along with them. Mabel was the one who came up with the idea and helped throw it all together with some help from her credit card. And she did make a compelling argument that seeing the father of all pin-up magazines with only one bunny would be a disservice to the man and his legacy, along with Mabel already having made her costume and was ready to party. 

The cherry on top though was guilting Dipper into it. Mabel didn't want them to break their twin tradition yet. They found it a rather odd idea to have this count as a sibling costume, yet somehow it worked for them. After all, they were unnaturally close, so it would make sense that they would partake in such costumes. Pacifica even, was moved by the argument to uphold such a long standing tradition between the two of them. 

No one else seemed to bat an eye though at the trio's get up. Wendy gave Dipper a friendly sock to the shoulder for being such a playboy, while Candy and Grenda fawned over Mabel and Pacifica's outfits and how sexy they looked. 

The night went on as they sailed out to sea. Festivities were pretty standard with confections and snacks of all kinds being served and drinks of the age appropriate kind were offered. However, once that line was crossed sending them into lawless territory, the real party began. Soda and juices were now being mixed with all sorts of alcohols of different types. Fireworks were being set off all over the ship as the party goers enjoyed the show. It was a grand time for all that were there.

Things escalated quickly when Wendy, being the most well versed of party goers there, brought out her special stash of "party supplies" for anyone to try. Candy and Grenda jumped at the chance to get a little loopy while Pacifica and Marius, being from high society, decided to stick to their drinks. Wendy respected the decisions of everyone and decided to let herself be the one to watch over her friends as they opened their minds and senses for the night. 

After the party got a little more relaxed, and those involved took their respective poisons, a question came up that made the group rather concerned. 

Where were Dipper and Mabel?

Marius and Pacifica, although a little tipsy, decided to go and look for them as the rest of the group seemed to be struggling to remain cognitive. Not wanting to risk anyone else getting lost or going overboard, the two wealthy teens set off to look for the twins. Plus their knowledge of the yacht made them better suited to look for the twins.

They checked out the most obvious and likely of places first. First the deck which turned up empty, then the bathrooms which were vacant, as well as the kitchen which only had the staff members who were now relaxing. The two were getting worried and anxious that something might have happened to them. They tried their best to remain calm and decided to go below deck to search. Descending the stairs, the two heard the sounds of heavy breathing and panting. As they made their way to the ship's storage area, the sounds became clearer and much more familiar. 

They entered the area, seeing movement further in. Marius and Pacifica didn't want to startle the people inside, lest they did something they would regret. They proceeded to sneak closer until they could get a clear view of who or what was down there. Soon they could fully recognize the sound of moaning and grunting as the vision of the figures became clear. A brunette teen, pumping away at a brown haired girl who's locks were barely contained by a bunny eared headband. 

It was Dipper and Mabel, locked together in the throws of passion with one another. Mabel, propped atop a covered box, had her legs and arms wrapped around Dipper's body as he thrusted his hips into her. Their faces wore a look of anguish and ecstasy as if this moment was so wonderful it hurt. They kissed each other all over feverishly as if they were in a hurry to enjoy each other as much as possible in a short period of time. 

"So this is what they do when they have no laws to worry about. They really are unnaturally close," Pacifica whispered to herself as Marius nodded in agreement. 

"Oh Dipper, that's the stuff. Rock the boat baby. Use the motion of the ocean." Mabel moaned out as she held him close to her. "It's been too long, I've missed this so much."

"Missed this? Wait, does that mean they have done this before?" Pacifica thought to herself as she continued watching with greater intent than before. 

"I know Mabel, I'm sorry," Dipper said, laying a kiss upon his sister. "I wish I could give you the love you deserve like we used to. But Pacifica is my girlfriend now. I couldn't just cheat on her like this."

"I know, but this night is all about having no rules. It ain't cheating and it definity ain't a sin to bone your sis out here. Just too bad we don't have an old timey car to fog up the windows on here. Oh well this is fine," Mabel said, returning the kiss. 

Pacifica felt a range of emotions stirring within her. She was confused at how long this was going on for, when it started, and how deep their feelings ran for one another. There was also a twinge of admiration for them. For them to be harboring these feelings for what seemed a painful amount of time to result in this expression of love, it must have taken a will of titanium for them to feel this way and not act upon them. 

The blonde bunny continued to watch in awe as she saw the siblings love one another in the truest form. She felt a small warmth as the sight of the twins with each other ignited a fire within her. She was still aware of the company she had as Marius was watching this display of affection as well. His presence quelled her to act upon her base desires but she made sure to burn the image into her mind for later. 

"Mabel, I'm getting close," Dipper grunted out as his hips quickened in pace. 

Pacifica's eyes widened as she was going to bear witness to her boyfriend cumming to his own sister. 

"Do it Dipper. Sink it like a battleship and fill me up," Mabel said in desperation. 

Again, the young heiress was shocked as she heard what Mabel said. She was expecting Dipper to pull out and cum on her. Never did she expect her boyfriend to cum inside his own sister raw. He didn't even do that to her. 

"M-Mabel!"

Dipper thrusted one last time, plunging his dick into Mabel until he bottomed out. He shuddered as his orgasm washed over his body. Mabel wrapped her arms around him even tighter, her toes clenching and her face looking as though she was holding back a scream which only escaped as a muffled squeal. 

The two held each tightly for a period of time as they rode out the pleasure they shared in. Their breathing was heavy as they tried to recover from such an exhausting session. Mabel loosened her embrace, allowing them to look at each other again. Their gaze was intense, both of them holding a passionate fire in their eyes for one another. They quenched the flame with an equally intense kiss. 

Pacifica kept watching as the two engaged in their post coitus kiss. She let out a sigh, catching her breath as well, having held it through the whole time she watched them share in orgasmic bliss. The fire she felt before was burning even hotter within her. She was relieved they were done as she was hoping to let loose this desire she was feeling as well. 

"You good to go again?" Dipper asked.

"What?!" Pacifca thought.

"You know it Double Dipper," Mabel replied with a wide smile on her face. "We don't know if we'll have another chance like this again. Let's make it count. Now all hands on deck"

Without even removing himself, Dipper began to thrust again as the two went for round two of love making. 

Pacifica continued to watch on, engrossed in her boyfriend and his sister and their movements. Her hand began to drift down her body as she was lost in the sounds and sight before her. However she was snapped out of it when Marius placed his hand on her shoulder. She jumped slightly but not enough to give away their presence. He tilted his head towards the stairwell, Pacifca nodding in agreement. They had seen enough, and felt the twins deserved their time alone. 

Sneaking back to the upper levels of the ship, Pacifica and Marius breathed easily now that they didn't need to mask their presence. The two looked at each other, a million questions were formulating in Pacifica's mind, while Marius seemed rather calm. 

"You seem rather okay with what we just saw," Pacifica said to the young Baron. 

"It doesn't bother me. I have seen in my family line that cousins and siblings have been married and have children. It isn't too unseen to have some inbreeding in a royal line," Marius said calm and collectively. 

"Better than my family line. Well then, the two of them will fit well in high society. But seriously, I wonder what they took to make them let loose like that?"

"I don't think they took anything. I think they were sober."

"Really?!" Pacifica exclaimed in disbelief. Her mind was even more rattled than before. 

She was thinking. They were making love of their own volition, completely without anything to inhibit or skew their mental faculties. Something about it seemed to make it all the more beautiful to her. She continued to process this. 

"Well… looks like I need to talk with them some time after we get back to land. But in the meantime we should get back to the group. But I got something to ask."

"Yes?"

"Perhaps in a few years, we can do this again? Maybe… have a wedding? Or two? You know, one official, and one not so official?"

"I think we can manage that," Marius said smiling, Pacifica returning one as well. 

The two went back to the rest of the group. Candy and Grenda had passed out by the time they got back. Wendy was relaxing as she continued to smoke her joint. 

"Finally back. Did you solve the Mystery Twins mystery?"

"Yeah," Pacifica responded. "Dipper was just helping Mabel feel better from a bit too much drinking."

"Poor Mabel. At least she's got such a good brother to take care of her."

"That she does," Pacifica said.

"You don't know the half of it," she thought to herself. 


End file.
